When conducting aluminum casting, etc., at a foundry, it is energy inefficient to remelt aluminum solidified into an ingot after being rendered molten by a manufacturer. Therefore, molten metal (melted metal) produced by a manufacturer is delivered to a foundry in molten form using a molten metal-transferring ladle. Examples include the molten metal-transferring ladle disclosed in Patent Document 1.
The molten metal-transferring ladle of Patent Document 1 is a pressure-tapping type molten metal-transferring ladle. As shown in FIG. 11, the ladle includes a ladle body 101 for containing melted metal; a large lid 102 covering the ladle body 101, an openable small lid 104 covering an inlet 103 provided in the middle portion of the large lid 102; a gas inlet 105 provided with the small lid 104 for pressurizing the surface of the melted metal (the molten metal surface) in the ladle; and a tapping portion 106 provided in the ladle body 101. The inlet 103 is an opening for use in pouring melted metal into the ladle body 101, observing the interior, removing aluminum oxide and the like, cleaning, heating by burner, etc.
For tapping melted metal, a pressurized gas supplying device is first connected to the gas inlet 105, and a pressurizing gas is introduced into a molten metal-transferring ladle to pressurize the molten metal surface, thereby supplying melted metal to a local furnace for a die-casting machine, etc., from a tap hole 107 of a tapping portion 106.    Patent Document 1: Japanese Unexamined Patent Publication No. 2002-254158